Gallstones

Contents

Introduction

Gallstones are hard deposits formed in the gallbladder, this is also known as cholelithiasis. If stones are seen in the common bile duct this condition is referred to as Choledocholithiasis. Gallstones can be made up of various constituents such as cholesterol, bilirubin, and mixed.Gallstones can form due to high levels of cholesterol from dietary intake. Another important factor that can contribute to gallstone formation is problems with the contraction of the gallbladder, how often and well the gallbladder empties itself. Other reasons may include, the presence of protein in the liver and bile that increases cholesterol crystallisation leading to stone formation. Gallstones are quite commonly occurring and can lead to a variety of complications.

The Gallbladder

The gallbladder is a pear-shaped organ that is present beneath the liver. You can locate the gallbladder between the lateral aspect of the rectus abdominis muscle and the right costal margins. Its main function is to store and concentrate bile. The liver produces and releases bile, a green substance that absorbs and breaks down lipids. Bile is made up of mostly bile acid, cholesterol and bilirubin.

The gallbladder opens into the cystic duct and biliary tree. It is made up of a fundus, body and neck. The fundus is along the transpyloric plane, which is halfway between the suprasternal notch and upper border of the pubic symphysis. Other structures that cross the transpyloric plane are the L1 vertebra, neck of the pancreas, first part of the duodenum, right and left colic flexures, hila of the left and right kidneys and hilum of spleen. The neck of the gallbladder leads into the cystic duct that then connects to the common hepatic duct, which then becomes the common bile duct. The gallbladder has a section that is called the Hartmann’s pouch, this is formed from an out pouching from the neck section. The Hartmann’s pouch is a common area for gallstones to become lodged.

Types of Gallstones

The most common type of stone is made up of cholesterol, they account for around 80% of gallstones. They occur when there is a problem in the balance of levels of cholesterol, bile acids and lipids. These stones are usually yellow or green in colour and consists of cholesterol monohydrate crystals.

Pigment gallstones are another type of stone; these are made mainly from bilirubin and from the crystallization of calcium bilirubinate. The colours of pigment stones are brown or black. The brown stones are usually associated with gallbladder infection and commonly associated gram-negative bacteria are Escherichia Coli and Klebsiella. Black stones are associated with red blood cell problems for example haemolysis and liver disease.

The third type is mixed gallstone which is a subclassification of the cholesterol stones and contains at least 50% of cholesterol by weight. Gallstones are also classified by their location as intrahepatic, gallbladder and bile duct stones. Intrahepatic are more commonly brown pigment stones, gallbladder stones are predominantly cholesterol and bile duct stones are mixed type.

Risk factors

Gallstones can occur due to excessive cholesterol and this can be due to diet. Risk factors include being overweight or obese, a high fat or cholesterol diet, rapid weight loss can lead to stone formation, a medical history of diabetes mellitus can put you at risk. Females are more likely to be at risk and pregnancy can contribute. A family history is linked to the condition as well. Other risk factors include liver disease for example, cirrhosis, or being over the age of 60.

A helpful mnemonic to remember the risk factors:

The Five F’s:

Fair

Fat

Fertile

Female

In her Forties

Signs and Symptoms

Gallstones present as asymptomatic majority of the time. If complications from gallstones arise then symptoms can appear.

For example in biliary colic, which occurs if the stones temporarily obstruct the cystic or common bile duct, patients experience the following signs and symptoms:

Intermittent pain in the upper right quadrant or epigastric region.

Pain radiates to the back.

Nausea

Vomiting

Bloating

Belching

Certain foods evoke symptoms

Acute Cholecystitis is caused due to inflammation of gallbladder wall, signs and symptoms are as follows:

Ascending/Acute Cholangitis is an infection of bile duct most commonly due to gallstones, signs and symptoms are as follows: Hallmark of this condition is Charcot’s triad, the common findings are:

Abdominal pain in the upper right quadrant

Fever

Jaundice

Patients also can have rigors and malaise

Investigations

Initial investigations to order are blood tests to measure bilirubin and liver function tests. The gold standard investigation for gallstones is abdominal ultrasound scan. Other helpful imaging tests are abdominal CT scan and gallbladder radionuclide scan. Endoscopic retrograde cholangiopancreatography (ERCP) is helpful to confirm the diagnosis of choledocholithiasis and also has a role in treatment.

Management

Surgery is usually the first choice after diagnosis, even if the patient does not have symptoms the surgeons advise surgery to avoid complications. Laparoscopic removal of the gallbladder after giving a general anaesthesia is performed. Non-surgical treatment is an option for patients with small, radiolucent cholesterol stones. Extracorporeal shockwave lithotripsy has been used in the management of choledocholithiasis. Bile duct stones can be removed with an (ERCP). The technique used an endoscope which is inserted into the mouth, and passed down the oesophagus, and through the stomach and into the duodenum. The second part of the duodenum is where the sphincter of oddi is located. The ampulla of vater is accessed via the sphincter of oddi, and the scope is passed up the biliary tree. MRCP (magnetic resonance cholangiopancreatography) is less invasive and many clinicians prefer to have this performed before an ERCP. The ERCP procedure can visualise the biliary system and remove any stones if present and insertion of stents to allow for the ducts to remain open is possible too.

Lifestyle changes are very important to advise patients on. Dietary advice is important; meal plans can be advised to encourage eating several times a day to replace large meals. Reducing fat in diet is crucial and increasing fibre can be helpful too. Avoiding food and drink that has a laxative effect like caffeine and sugary foods, is useful, as after treatment of gall bladder removal patients may experience watery diarrhoea.

Complications

Gallstone ileus is a complication of a gangrenous gallstone. A fistula forms between the gallbladder and duodenum this allows for the stone to enter the intestines. Once the gallstone reaches a diameter of more than 2.5cm, there is a risk of intestinal obstruction.

Gallstone pancreatitis is another potential complication that can occur if the gallstone is passing through the bile duct and becomes lodged in the Sphincter of Oddi.

Choledocholithiasis occurs if the gallstone are formed within the common bile duct that leads to obstruction and infection. This can be life-threatening and emergency medical care is required. Patients may present with abdominal pain, fever, jaundice, anorexia, nausea and vomiting. Transabdominal ultrasound scan is recommended to examine the gallbladder and surrounding structures. To treat stone extraction is needed, lithotripsy is an option where the stone is fragmented or surgery by removing the gallbladder with a cholecystectomy. Stenting can be done to the common bile duct to provide drainage and prevention of future obstruction.

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